dynbuf: introduce internal generic dynamic buffer functions

A common set of functions instead of many separate implementations for
creating buffers that can grow when appending data to them. Existing
functionality has been ported over.

In my early basic testing, the total number of allocations seem at
roughly the same amount as before, possibly a few less.

See docs/DYNBUF.md for a description of the API.

Closes #5300

1 files changed, 21 insertions, 34 deletions

diff --git a/lib/curl_ntlm_wb.c b/lib/curl_ntlm_wb.c
index f820b842e..062ac7b94 100644
--- a/lib/curl_ntlm_wb.c
+++ b/lib/curl_ntlm_wb.c
@@ -261,15 +261,11 @@ done:
 static CURLcode ntlm_wb_response(struct Curl_easy *data, struct ntlmdata *ntlm,
                                  const char *input, curlntlm state)
 {
-  char *buf = malloc(NTLM_BUFSIZE);
   size_t len_in = strlen(input), len_out = 0;
-
-#if defined(CURL_DISABLE_VERBOSE_STRINGS)
-  (void) data;
-#endif
-
-  if(!buf)
-    return CURLE_OUT_OF_MEMORY;
+  struct dynbuf b;
+  char *ptr = NULL;
+  unsigned char *buf = (unsigned char *)data->state.buffer;
+  Curl_dyn_init(&b, MAX_NTLM_WB_RESPONSE);
 
   while(len_in > 0) {
     ssize_t written = swrite(ntlm->ntlm_auth_hlpr_socket, input, len_in);
@@ -285,10 +281,8 @@ static CURLcode ntlm_wb_response(struct Curl_easy *data, struct ntlmdata *ntlm,
   }
   /* Read one line */
   while(1) {
-    ssize_t size;
-    char *newbuf;
-
-    size = sread(ntlm->ntlm_auth_hlpr_socket, buf + len_out, NTLM_BUFSIZE);
+    ssize_t size =
+      sread(ntlm->ntlm_auth_hlpr_socket, buf, data->set.buffer_size);
     if(size == -1) {
       if(errno == EINTR)
         continue;
@@ -297,48 +291,41 @@ static CURLcode ntlm_wb_response(struct Curl_easy *data, struct ntlmdata *ntlm,
     else if(size == 0)
       goto done;
 
-    len_out += size;
-    if(buf[len_out - 1] == '\n') {
-      buf[len_out - 1] = '\0';
-      break;
-    }
+    if(Curl_dyn_addn(&b, buf, size))
+      goto done;
 
-    if(len_out > MAX_NTLM_WB_RESPONSE) {
-      failf(data, "too large ntlm_wb response!");
-      free(buf);
-      return CURLE_OUT_OF_MEMORY;
+    len_out = Curl_dyn_len(&b);
+    ptr = Curl_dyn_ptr(&b);
+    if(len_out && ptr[len_out - 1] == '\n') {
+      ptr[len_out - 1] = '\0';
+      break; /* done! */
     }
-
-    newbuf = Curl_saferealloc(buf, len_out + NTLM_BUFSIZE);
-    if(!newbuf)
-      return CURLE_OUT_OF_MEMORY;
-
-    buf = newbuf;
+    /* loop */
   }
 
   /* Samba/winbind installed but not configured */
   if(state == NTLMSTATE_TYPE1 &&
      len_out == 3 &&
-     buf[0] == 'P' && buf[1] == 'W')
+     ptr[0] == 'P' && ptr[1] == 'W')
     goto done;
   /* invalid response */
   if(len_out < 4)
     goto done;
   if(state == NTLMSTATE_TYPE1 &&
-     (buf[0]!='Y' || buf[1]!='R' || buf[2]!=' '))
+     (ptr[0]!='Y' || ptr[1]!='R' || ptr[2]!=' '))
     goto done;
   if(state == NTLMSTATE_TYPE2 &&
-     (buf[0]!='K' || buf[1]!='K' || buf[2]!=' ') &&
-     (buf[0]!='A' || buf[1]!='F' || buf[2]!=' '))
+     (ptr[0]!='K' || ptr[1]!='K' || ptr[2]!=' ') &&
+     (ptr[0]!='A' || ptr[1]!='F' || ptr[2]!=' '))
     goto done;
 
-  ntlm->response = aprintf("%.*s", len_out - 4, buf + 3);
-  free(buf);
+  ntlm->response = strdup(ptr + 3);
+  Curl_dyn_free(&b);
   if(!ntlm->response)
     return CURLE_OUT_OF_MEMORY;
   return CURLE_OK;
 done:
-  free(buf);
+  Curl_dyn_free(&b);
   return CURLE_REMOTE_ACCESS_DENIED;
 }